Infernal-Expansion VS RepurposedStructures

If you want more Nether biomes, check out Infernal Expansion, Gardens of the Dead and Nourished Nether. IE adds a number of mobs and a glowstone canyon biome. Gardens of the Dead is a small mod that has some very nice mushrooms. Nourished Nether adds a lot of new blocks to existing biomes.

A good few are Quark, JEI, Appleskin, Waystones, MrCrayfish's Furniture Mod, Nature's Compass, Iron Chests, Aquaculture 2, Comforts, Lycanites Mobs (1.19 version isn't fully out yet but sometime in the future it will be), Weeping Angels, Better Animals Plus, Neat, MrCrayfish's Gun Mod, Goblin Traders, Biomes O Plenty (You have to select Biomes O' Plenty World Type for them to generate), Giant Spawn, Nightmare Epic Siege, Let Sleeping Dogs Lie, Alex's Mobs, Infernal Expansion, Earth Mobs, Oh The Biomes You'll Go, Improved Mobs (You can disable Difficulty Meter in config file), Eyes In The Darkness, and lastly, Observed.

Other smaller less major mob mods could be https://www.curseforge.com/minecraft/mc-mods/aquaculture https://www.curseforge.com/minecraft/mc-mods/mowzies-mobs https://www.curseforge.com/minecraft/mc-mods/endergetic https://www.curseforge.com/minecraft/mc-mods/environmental https://www.curseforge.com/minecraft/mc-mods/infernal-expansion

Infernal Expansion (by InfernalStudios)

I think I tracked the lag down to this Infernal Expansion issue.

Looks like either Additional Structures or Repurposed Structures

For now, I use Nullscape for generation, Repurposed Structures to add more structures, and Basic End Ores to make mining in The End worthwhile.

Repurposed Structures (Forge) (by telepathicgrunt)

I'm pretty sure they spawn in unloaded chunks. Also, if you want more structures I'd suggest using Repurposed Structures, Bygone Nether, and The Graveyard. Also, to make it easier to find these structures you can use Explorer's Compass. If you want to add more mobs I'd suggest Dragon Mounts and Lava Monsters. Also, if you don't want to lose your items when you die you should use either GraveStone or Corpse.

Forge: https://www.curseforge.com/minecraft/mc-mods/repurposed-structures

I don't have mods for everything you have asked for, but you can check some of the ones I know (1.18.2 since Terralith isn't 1.19 yet, I am unsure if it will be but I think it will) Terralith is a mod that adds very unqiue biomes without adding any new blocks to the game, there are some very interesting forests, deserts and even volcanoes Repurposed-Structures is a mod that adds new dungeons and other structures which as far as I know adds 0 blocks as well Better Village is a mod that makes villagers a lot more interesting in my opinion, I have never used it but it looks amazing from the images. Ambient Sounds adds a variety of sounds to the game and it make it feel a lot more alive Alternatively, you can use Dynamic Surroundings if you are playing 1.16.5, I like that mod a lot more

And finally, something like Repurposed Structures that adds more variants of vanilla structures to the game.